Green Card Holders
Green Card (GC) holders are treated the same as US citizens for tax purposes, even if they live abroad. They are required to disclose their worldwide income and submit a tax return to the IRS annually.
GC holders will remain subject to these tax-related obligations until they receive an official statement from the US Citizenship and Immigration Service (USCIS) to the effect that their Green Card has been revoked or relinquished.
Еven if the USCIS no longer considers a Green Card to be valid (for immigration purposes), the tax-related obligations that come with it will continue to apply - until an official written statement from the USCIS confirms that the Green Card has been revoked or relinquished. Only then will the tax-related obligations come to an end. Noncompliance with tax obligations may give rise to high penalties - the same as for US citizens.
Even when a Green Card holder does not live in the USA, his or her worldwide income will, as a general principle, be subject to taxation in the USA. In order to avoiding double taxation, it will generally be possible to offset taxes paid abroad (as well as utilize deductions and exclusions available to US citizen expatriates).